The study employs two systems of differentiation in bacteria: sporulation in Bacillus species and encystment in Azotobacter vinelandii. Bacitracin production at the onset of sporulation of B. licheniform is the consequence of proteolysis of a protein normally present in vegetative cells of the organism. We propose to isolate, characterize, and study the mechanism by which the limit peptide antibiotic is produced. Studies of encystment of A. vinelandii will include a continuation of the analysis of the metabolic fate of B-hydroxybutyrate (BHB), the specific encystment initiator in this organism. A study will be initiated of the shut-down of nitrogenase during encystment, its possible turnover, and its reactivation or synthesis during germination of cysts of A. vinelandii. We have devised procedures for the isolation of folded chromosomes of A. vinelandii. Efforts will be made to study the extent of chromosome-membrane interaction at various stages of the life cycle of the organism. Cysts contain relatively high levels of poly-hydroxybutyrate but require exogenous energy sources during germination. We plan to investigate their germination process by determining the nature of other substrates stored within them and the means by which these materials are mobilized. BIBLIOGRAPHIC REFERENCES: Page, W.J., and H.L. Sadoff, 1976. Physiological factors affecting transformation of Azotobacter vinelandii. J. Bacteriol. 125:1080-1087. Page, W.J., and H.L. Sadoff. 1976. Control of transformation competence in Azotobacter vinelandii by nitrogen catabolite derepression. J. Bacteriol. 125:1088-1095.